1. Field of the Invention
The present invention relates to manufacture of an improved form of fibrous pulp utilizing poly(p-phenylene terephthalamide) (PPD-T). Pulps have traditionally been made from spun aramid fibers which are mechanically refined and take the form of a fiber backbone or stalk with fibrils extending therefrom. Pulp of the present invention is not made from spun fibers and provides bundles of pulp particles which have a high proportion of fibrils and a very low proportion of stalks.
2. Description of the Prior Art
U.S. Pat. Nos. 5,073,440 and 5,135,687 issued on the applications of Kiu-Seung Lee, teach continuous fibers comprising a para-aramid and poly(vinyl pyrrolidone) and a method for spinning such fibers.
European Patent Application Nos. 381,172 and 396,020, published Sep. 8, 1990 and Nov. 7, 1990, disclose homogeneous alloys of certain aromatic polyamides and poly(vinyl pyrrolidone) and continuous fibers and films made from such alloys.
U.S. Pat. No. 4,511,623, issued on the application of H. S. Yoon, teaches the preparation of short aramid fibers by subjecting a solution of the polymerizing aramid to high mechanical shearing.
U.S. Pat. No. 5,028,372, issued on the application of Brierre et al. teaches the manufacture of pulp by subjecting anisotropic solutions of polymerizing para-aramid to shear forces for the purpose of orienting polymer chains as they grow.